1. Field of the Invention
The present invention relates to a file sharing system for managing a data file shared among a plurality of clients.
2. Description of the Related Art
As techniques relating to a file sharing system, there are known those disclosed in, for example, Japanese Patent Application Laid-Open (JP-A) Nos. 2003-330787 and 2003-203029. A file sharing method disclosed in JP-A-2003-330787 includes a system connected to a LAN, and the system searches a server having a capability potentially available for data sharing and distributes or collects data to the server. A file sharing method disclosed in JP-A-2003-203029 includes further connecting a switch to a network to which clients and servers are connected and transferring an access request from each of the clients to an appropriate server using this switch.
With the method disclosed in JP-A-2003-330787, file sharing can be realized by distributing and arranging a data file to a plurality of servers. However, in the file sharing system disclosed in JP-A-2003-330787, upper limits are set to the number of connected disks and a file capacity that can be managed by one server, respectively. There is also a limit to the capacity of a file system that can be handled by a single file system view. Due to this, the method disclosed in JP-A-2003-330787 has a disadvantage in that it is difficult to improve user's satisfaction with the file sharing system.
With the method disclosed in JP-A-2003-203029, all access requests from the clients are controlled to be transferred to appropriate servers using the single switch. Due to this, a processing load concentrates on the switch. Particularly if the number of clients is quite large, the processing load may possibly exceed an allowable level for the processing of the switch. If the excess of the processing load over the allowable level for the processing causes switch operation to stagnate, a response to the clients is disadvantageously deteriorated and service interruption disadvantageously occurs.